Add support for the Projection element

It's a part of the Google Spatial Media V2 spec:
https://github.com/google/spatial-media/blob/master/docs/spherical-video-v2-rfc.md

Change-Id: I52f05e34b19239af09774da2f88eb584a0bfa628

webm_parser/include/webm/dom_types.h

@@ -883,6 +883,66 @@ struct Colour {
   }
 };
 
+/**
+ A parsed \WebMID{ProjectionType} element.
+ */
+enum class ProjectionType : std::uint64_t {
+  /**
+   Rectangular.
+   */
+  kRectangular = 0,
+
+  /**
+   Equirectangular.
+   */
+  kEquirectangular = 1,
+
+  /**
+   Cube map.
+   */
+  kCubeMap = 2,
+};
+
+/**
+ A parsed \WebMID{Projection} element.
+ */
+struct Projection {
+  /**
+   A parsed \WebMID{ProjectionType} element.
+   */
+  Element<ProjectionType> type;
+
+  /**
+   A parsed \WebMID{ProjectionPrivate} element.
+   */
+  Element<std::vector<std::uint8_t>> projection_private;
+
+  /**
+   A parsed \WebMID{ProjectionPoseYaw} element.
+   */
+  Element<double> pose_yaw;
+
+  /**
+   A parsed \WebMID{ProjectionPosePitch} element.
+   */
+  Element<double> pose_pitch;
+
+  /**
+   A parsed \WebMID{ProjectionPoseRoll} element.
+   */
+  Element<double> pose_roll;
+
+  /**
+   Returns true if every member within the two objects are equal.
+   */
+  bool operator==(const Projection& other) const {
+    return type == other.type &&
+           projection_private == other.projection_private &&
+           pose_yaw == other.pose_yaw && pose_pitch == other.pose_pitch &&
+           pose_roll == other.pose_roll;
+  }
+};
+
 /**
  A parsed \WebMID{FlagInterlaced} element.
  */
@@ -1113,6 +1173,11 @@ struct Video {
    */
   Element<Colour> colour;
 
+  /**
+   A parsed \WebMID{Projection} element.
+   */
+  Element<Projection> projection;
+
   /**
    Returns true if every member within the two objects are equal.
    */
@@ -1128,7 +1193,8 @@ struct Video {
            display_height == other.display_height &&
            display_unit == other.display_unit &&
            aspect_ratio_type == other.aspect_ratio_type &&
-           frame_rate == other.frame_rate && colour == other.colour;
+           frame_rate == other.frame_rate && colour == other.colour &&
+           projection == other.projection;
   }
 };
 

webm_parser/include/webm/id.h

@@ -704,6 +704,48 @@ enum class Id : std::uint32_t {
    */
   kLuminanceMin = 0x55DA,
 
+  /**
+   \WebMID{Projection} element ID.
+
+   \WebMTable{Master, 5, No, No, No, , }
+   */
+  kProjection = 0x7670,
+
+  /**
+   \WebMID{ProjectionType} element ID.
+
+   \WebMTable{Unsigned integer, 6, Yes, No, No, , 0}
+   */
+  kProjectionType = 0x7671,
+
+  /**
+   \WebMID{ProjectionPrivate} element ID.
+
+   \WebMTable{Binary, 6, No, No, No, , }
+   */
+  kProjectionPrivate = 0x7672,
+
+  /**
+   \WebMID{ProjectionPoseYaw} element ID.
+
+   \WebMTable{Float, 6, Yes, No, No, , 0}
+   */
+  kProjectionPoseYaw = 0x7673,
+
+  /**
+   \WebMID{ProjectionPosePitch} element ID.
+
+   \WebMTable{Float, 6, Yes, No, No, , 0}
+   */
+  kProjectionPosePitch = 0x7674,
+
+  /**
+   \WebMID{ProjectionPoseRoll} element ID.
+
+   \WebMTable{Float, 6, Yes, No, No, , 0}
+   */
+  kProjectionPoseRoll = 0x7675,
+
   /**
    \MatroskaID{Audio} element ID.